Inactivation of MS2 Bacteriophage and Adenovirus with Silver and Copper in Solution and Embedded in Ceramic Water Filters

Abstract

This study investigates the inactivation of adenovirus by silver and copper in aqueous solution, compares silver and copper disinfection of adenovirus to the MS2 phage, and quantifies MS2 transport through porous ceramic filters fabricated with silver nitrate and copper nitrate added prior to firing the clay-sawdust-water mixture. The MS2 phage is commonly used as a model virus for testing the efficacy of point-of-use water treatment technologies. However, results show that MS2 phage is not a representative virus, specifically as a surrogate for silver ion inactivation of viruses. At safe drinking water concentrations, after 8 h of exposure, silver and copper resulted in a 0.91- and 1.61-log10 reduction of viable adenovirus, respectively. Under the same conditions, silver and copper resulted in a 0.42- and 1.46-log10 reduction of viable MS-2 phage, respectively. Transmission electron microscopy (TEM) images suggest the mechanism of adenovirus inactivation may be related to damage/removal of the viral fibers. Removal of MS2 phage by ceramic water filters is modest, 71.95% and 75.98% by silver- and copper-embedded filters, respectively. These results indicate that ionic silver is a better viral disinfectant than previously known based on data for the MS2 phage alone and that copper, both alone and in combination with silver, may further improve viral disinfection.